We measure the mass of the top quark in lepton + jets final states using the full sample of p (p) over bar collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at ...root s = 1.96 TeV, corresponding to 9.7 fb(-1) of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from t (t) over bar production or background. The overall jet energy scale is constrained in situ by the mass of theW boson. We measure m(t) = 174.98 +/- 0.76 GeV. This constitutes the most precise single measurement of the top-quark mass.
We present a study of the inclusive production of the X(4140) state with the decay to the J/psi phi final state in hadronic collisions. Based on 10.4 fb(-1) of p (p) over bar collision data collected ...by the D0 experiment at the Fermilab Tevatron collider, we report the first evidence for the prompt production of an X(4140) state and find the fraction of X(4140) events originating from b hadrons to be f(b) = 0.39 +/- 0.07 (stat) +/- 0.10 (syst). The ratio of the nonprompt X(4140) production rate to the B-s(0) yield in the same channel is R = 0.19 +/- 0.05 (stat) +/- 0.07 (syst). The values of the mass M = 4152.5 +/- 1.7 (stat)(-5.4)(+/- 6.2)(syst) MeV and width Gamma = 16.3 +/- 5.6 (stat) +/- 11.4 (syst) MeV are consistent with previous measurements.
The inclusive cross section of top quark-antiquark pairs produced in p (p) over bar collisions at root s = 1.96 TeV is measured in the lepton + jets and dilepton decay channels. The data sample ...corresponds to 9.7 fb(-1) of integrated luminosity recorded with the D0 detector during Run II of the Fermilab Tevatron Collider. Employing multivariate analysis techniques we measure the cross section in the two decay channels and we perform a combined cross section measurement. For a top quark mass of 172.5 GeV, we measure a combined inclusive top quark-antiquark pair production cross section of sigma(t<(t)over bar) = 7.26 +/- 0.13(stat)(-0.50)(+0.57) (syst) pb which is consistent with standard model predictions. We also perform a likelihood fit to the measured and predicted top quark mass dependence of the inclusive cross section, which yields a measurement of the pole mass of the top quark. The extracted value is m(t) = 172.8 +/- 1.1(theo)(-3.1)(+3.3) (exp) GeV.
We present a measurement of top quark polarization in tt¯ pair production in pp¯ collisions at s=1.96 TeV using data corresponding to 9.7 fb−1 of integrated luminosity recorded with the D0 detector ...at the Fermilab Tevatron Collider. We consider final states containing a lepton and at least three jets. The polarization is measured through the distribution of lepton angles along three axes: the beam axis, the helicity axis, and the transverse axis normal to the tt¯ production plane. This is the first measurement of top quark polarization at the Tevatron using lepton+jet final states and the first measurement of the transverse polarization in tt¯ production. The observed distributions are consistent with standard model predictions of nearly no polarization.
Here, the lifetime of the B$0\atop{S}$ meson is measured in the decay channel B$0\atop{S}$→J/ψπ+π- with 880 ≤ Mπ+π- ≤ 1080 MeV/c2, which is mainly a CP-odd state and dominated by the f0(980) ...resonance. In 10.4 fb-1 of data collected with the D0 detector in Run II of the Tevatron, the lifetime of the B$0\atop{S}$ meson is measured to be τ(B$0\atop{S}$) = 1.70 ± 0.14(stat) ± 0.05(syst) ps. Neglecting CP violation in B$0\atop{S}/$\bar{B}$0s mixing, the measurement can be translated into the width of the heavy mass eigenstate of the B$0\atop{S}$, ΓH = 0.59 ± 0.05(stat) ± 0.02(syst) ps-1.
We present the first search for CPT-violating effects in the mixing of B0s mesons using the full Run II data set with an integrated luminosity of 10.4 fb-1 of proton-antiproton collisions collected ...using the D0 detector at the Fermilab Tevatron Collider. We measure the CPT-violating asymmetry in the decay B0s → µ±D±s as a function of celestial direction and sidereal phase. We find no evidence for CPT-violating effects and place limits on the direction and magnitude of flavor-dependent CPTand Lorentz-invariance violating coupling coefficients. We find 95% confidence intervals of Δa⊥ < 1.2 × 10-12 GeV and (-0.8 < ΔaT - 0.396ΔaZ < 3.9) × 10-13 GeV.
We present a measurement of the effective weak mixing angle parameter sin2θ$^{ℓ}_{eff}$ in $p$$\bar{p}$ → Z/γ* → μ+μ- events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at ...the Fermilab Tevatron Collider and corresponding to 8.6 fb-1 of integrated luminosity. The measured value of sin2θ$^{ℓ}_{eff}$ μμ = 0.23016 ± 0.00064 is further combined with the result from the D0 measurement in $p$$\bar{p}$ → Z/γ* → e+ e- events, resulting in sin2θ$^{ℓ}_{eff}$ comb = 0.23095 ± 0.00040. This combined result is the most precise measurement from a single experiment at a hadron collider and is the most precise determination using the coupling of the Z/γ* to light quarks.
We present a study of the X±(5568) using semileptonic decays of the Bs0 meson using the full run II integrated luminosity of 10.4 fb−1 in proton-antiproton collisions at a center of mass energy of ...1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. We report evidence for a narrow structure, X±(5568), in the decay sequence X±(5568)→Bs0π± where Bs0→μ∓Ds±X, Ds±→ϕπ± which is consistent with the previous measurement by the D0 Collaboration in the hadronic decay mode, X±(5568)→Bs0π± where Bs0→J/ψϕ. The mass and width of this state are measured using a combined fit of the hadronic and semileptonic data, yielding m=5566.9−3.1+3.2(stat)−1.2+0.6(syst) MeV/c2, Γ=18.6−6.1+7.9(stat)−3.8+3.5(syst) MeV/c2 with a significance of 6.7σ.
We present the first measurement of the CP violating charge asymmetry in B±→μ±νμD0 decays using the full Run II integrated luminosity of 10.4 fb−1 in proton-antiproton collisions collected with the ...D0 detector at the Fermilab Tevatron Collider. We measure a difference in the yield of B− and B+ mesons in these decays by fitting the reconstructed invariant mass distributions. This results in an asymmetry of AμD0=−0.14±0.20%, which is consistent with standard model predictions.
We present a measurement of top quark polarization in t (t) over bar pair production in p (p) over bar collisions at root s = 1.96 TeV using data corresponding to 9.7 fb(-1) of integrated luminosity ...recorded with the D0 detector at the Fermilab Tevatron Collider. We consider final states containing a lepton and at least three jets. The polarization is measured through the distribution of lepton angles along three axes: the beam axis, the helicity axis, and the transverse axis normal to the t (t) over bar production plane. This is the first measurement of top quark polarization at the Tevatron using lepton + jet final states and the first measurement of the transverse polarization in t (t) over bar production. The observed distributions are consistent with standard model predictions of nearly no polarization.
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